INSECTA. 243 



mandibles and maxillse(l) for mastication: the inferior wings 

 are simply folded crosswise, and the cases, always horizontal, 

 are crustaceous. They experience a complete metamorphosis. 



In the sixth or the 0rthoptera(2), there are six legs; 

 four wings, the two superior in the form of cases, and mandi- 

 bles and jaws for mastication, covered at the extremity by a 

 galea; the inferior wings are folded in two directions, or simply 

 in their length, and the inner margins of the cases, usually co- 

 riaceous, are crossed. They only experience a semi- meta- 

 morphosis. 



In the seventh or the Hemiptera, there are six legs and 

 four wings, the two superior in the form of crustaceous cases, 

 with membranous extremities, or similar to the inferior, but 

 larger and firmer ; the mandibles and jaws are replaced by 

 setae forming a sucker, enclosed in a sheath composed of one 

 articulated, cylindrical or conical piece, in the form of a ros- 

 trum. 



(1) The maxillae of coleopterous Insects, in conjunction with the mandibles, 

 usually have this triturating- function assigned to them. M. Hentz, j> distinguished 

 American entomologist, Trans. Phil. Soc, III, part ii, p. 4*0, is of the opinion 

 that in many cases the maxillae must be considered as r.iere appendages to the 

 tongue, and that their office is to assist in deglutition, seldom serving to grind or 

 lacerate, except in the Melolonthidae, Rutelidse, and some others, where there seems 

 to be a departure from their primary use. In corroboration of this idea he adduces 

 the configuration of the maxillae of several Insects, in which he has been fortunate 

 enough to detect a retractile appendage hitherto unknown. The first is the Can- 

 tharis marginata, Fab., whose maxillae, when dried, offer but one bifid lobe; if, 

 however, the abdomen and thorax of the recent animal be gradually compressed, 

 a soft, elastic, sub-conic body is protruded from the cleft of that lobe, more than 

 half its length, and extending beyond the palpi; a second appendage of the same 

 kind, and about half its length, projects at right angles from the base of the first, 

 which is directed forwards: both are covered with hairs. The second is the Canth. 

 Limaculata, Fab., in which this appendage is still more sensibly and easily display- 

 ed, protruding by pressure from each maxilla in the form of a tapering filament 

 covered with fine hairs, susceptible of considerable extension, reaching* beyond 

 the middle of the antennae, and consequently more than double the length of the 

 maxilla itself. I have verified these facts in this last species. The use of these 

 organs in collecting nourishment from flowers is evident. See Trans. Phil. Soc. 

 ut sup. pi. XV, f. i, e, and f. ii, e. Am. Ed. 



(2) De Geer established this order under the name of Dermaptera, improperly 

 changed by Olivier to that of Or thopf era. We preserve the latter, however, as na- 

 turalists have generally adopted it. 



